21733731 Kit | Genuine Volvo Penta Part

🔧 Product Description

Genuine Volvo Penta Neutra-Salt engine flushing kit, listed for engines with a 1 inch or 1 1/4 inch water inlet hose and weighing 3.037 kg. It suits both freshwater and saltwater cooled engines that have an engine-driven seawater pump and can be installed on inboards and sterndrives. The kit contains 0.95 litre of Neutra-Salt concentrate, a 2.85 litre reservoir with mounting bracket, eight feet of hose, a brass seawater inlet tee fitting, a connecting hose for the power-steering cooler, hose clamps, a rocker switch, a Flush switch, a wiring harness with fuses and a solenoid. It flushes the engine with the boat still in the water, leaving a corrosion inhibitor on the power-steering and oil cooler, engine block, exhaust manifold and risers, thermostat housing and the circulating and raw water pumps.

⚙️ Key Features

• For engines with a 1 inch or 1 1/4 inch water inlet hose
• For freshwater and saltwater cooled engines with an engine-driven seawater pump
• Includes 0.95 litre concentrate, 2.85 litre reservoir and bracket, eight feet of hose, brass inlet tee, hoses, clamps, switches, wiring harness with fuses and solenoid
• Flushes with the boat still in the water
• Typically 10 to 15 flushes before a refill
• 3.037 kg
• Flushes the engine with the boat still in the water
• Helps protect the engine from saltwater damage
• Helps prevent corrosion by removing salt deposits and leaving a protective corrosion inhibitor on metal surfaces including the power-steering and oil cooler, engine block, exhaust manifold and risers, thermostat housing, and circulating and raw-water pumps
• Installs easily and operates smoothly
• Concentrate supplied: 0.95 litre
• Fits water inlet hose: 1 inch or 1 1/4 inch
• Reservoir: 2.85 litre
• Fits: Inboards and sterndrives, freshwater or saltwater cooled, with an engine-driven sea-water pump and a 1 inch or 1 1/4 inch water inlet hose

📋 Kit Contents

• 1 x 0.95-litre Neutra-Salt concentrate bottle - replacement Volvo Penta 21687793
• 1 x 2.85-litre concentrate reservoir
• 1 x reservoir mounting bracket
• 1 x 8-foot supply hose
• 1 x brass seawater-inlet tee
• 1 x connecting hose for the power-steering cooler circuit
• Hose clamps for the supplied plumbing
• 1 x helm rocker switch
• 1 x Flush-labelled switch actuator
• 1 x fused wiring harness
• 1 x electric metering solenoid
• Related 3.8-litre concentrate refill - Volvo Penta 21687796

🔌 Function

Meters Neutra-Salt concentrate into the incoming seawater so that salt residue is neutralised and flushed from the cooling and exhaust passages, leaving a corrosion-inhibiting coating behind.

⚠️ Common Signs of Failure

• Reservoir level not dropping when the Flush switch is held
• Solenoid silent or not opening on the switch
• Seawater weeping at the inlet tee fitting or its clamps
• Salt deposits still building up in the cooling passages after flushing

🛠️ Service Notes

• To operate, hold the dash switch for 45 seconds with the engine at idle and an adequate supply of seawater, then stop the engine before releasing the switch
• Refill concentrate is 21687793 in the quart size and 21687796 in the gallon size
• Check the inlet hose size is 1 inch or 1 1/4 inch before ordering
• To operate, push and hold the dash-mounted Flush switch for 45 seconds while running the engine at idle speed, making sure the engine has an adequate supply of sea water
• Turn the engine off before disengaging the Flush switch
• For best results use the system after every outing; boat owners typically get 10 to 15 flushes before a refill is needed
• Only for engines with an engine-driven sea-water pump

🔄 Supersession & Cross Reference

OEM Supersession Chain

• 21733731 → Supersedes 3808823 → Supersedes 41103100

OEM / Related Numbers

• 3808823 earlier number superseded by this part
• 41103101 earlier number superseded by this part
• 41103100 earlier number superseded by this part
• 21687793 related reference
• 21687796 related reference

📦 Condition

• Genuine Volvo Penta part
• Brand new
• Supplied in original or equivalent packaging